The former investment banker charged in a $1 million insider trading scheme with his Long Island father said on Wednesday that he plans to take the stand and testify on his own behalf.

The testimony will allow Sean Stewart, who announced his plans in an exchange with Manhattan U.S. District Judge Laura Taylor Swain, to try to personally convince jurors that he didn’t know his father was trading on unannounced mergers Sean told him about.

Prosecutors, who are about to finish their case, have charged Stewart, 35, of Manhattan, and his father Robert Stewart, 61, of North Merrick, where Sean grew up, with trading on information Sean learned at JPMorgan Chase and Perella Weinberg Partners.

Robert, the father, pleaded guilty, but is not testifying. Richard Cunniffe, a friend of Robert’s who executed trades in his account and took home the lion’s share of profits, has also pleaded guilty and wore a wire as a cooperating witness.

Cunniffe has said he barely knew Sean and never spoke to him about the tips, but was told by Robert that Sean was the source. In a secret recording last year, Robert said Sean once complained about his dad not trading on a tip Sean gave him “on a silver platter.”

On Wednesday, however, Cunniffe acknowledged that on a later recording, Robert said the opposite. In that recording, he told Cunniffe that Sean talked about deals because he gets “angry at times, angry at the industry.”

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“It’s just stuff he mentions as he goes around, you know, ‘Oh, I am working on this, I am working on that,’ ” Robert Stewart said, according to a transcript provided to jurors. “ . . . I never told him, like, I’ve done anything.”

Under questioning by prosecutors, Cunniffe said he believed those statements were disingenuous, because Stewart had become suspicious of his co-conspirator’s efforts to steer their conversation.

“I could tell that I had made Bob nervous, and I was trying to relax him,” Cunniffe testified. “Obviously something was up, and he had picked up on it. . . . I sensed he was becoming a little bit suspicious about why I was asking.”